Semiconductor devices such as, but not limited to, 3D memory stacks include multilayer film stacks that may include tens or hundreds of film layers. Such multilayer film stacks may be susceptible to embedded defects on any of the film layers and it is typically desirable to monitor both defect frequency and the depths at which the defects occur. For example, defect depth data may pinpoint particular fabrication steps susceptible to defects. However, it is typically undesirable and/or impractical to inspect multilayer samples after the deposition of each layer. Accordingly, multilayer samples may typically be inspected for defects after the deposition of multiple layers or even the entire film stack.
As the number of film stacks increase, determining depth information of embedded defects presents increasing challenges. For example, depths of embedded defects in multilayer stacks may typically be accurately determined using an invasive approach such as focused ion-beam (FIB) milling. However, invasive measurement techniques may be time-consuming and may be applied only to representative test samples rather than production samples. It is therefore desirable to create systems and methods that cure the deficiencies above.